There are various types of equipment and techniques to test the durability of urban infrastructure including buildings and railroads; roads; riverside and coastal levees, etc. Conventionally, to check the state of a wall surface of a building and detect a deteriorated state, for example, at periodic intervals, an inspector uses testing instruments to perform tests from the external appearance.
Meanwhile, in research and industrial fields, measuring methods and the like that use sensor devices are being developed (for example, refer to Takashi MORITO, Shunsuke SARUWATARI, Masateru MINAMI, Hiroyuki MORIKAWA, “10 Years from Smart Dust: Deployment of Wireless Sensor Network”, Morikawa Laboratory, Technical Research Report No. 2008002, May 1, 2008). For example, when detecting the state of a subject to a greater extent or when detecting an internal state, in addition to the installation of an inspection opening and schemes that involve the use of a laser, radar, etc. to perform nondestructive testing, schemes that involve embedding sensors are used.
Nonetheless, equipping in each node, which has a limit to its mass, a circuit that detects failure of an apparatus of the node is difficult. Therefore, with the conventional techniques above, controlling the transmission of erroneous data resulting from an abnormality at a node is difficult.